java项目中Excel文件的导入导出

package poi.excel;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.http.HttpServletRequest;

import org.apache.log4j.Logger;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.hssf.usermodel.HSSFRichTextString;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.util.HSSFColor;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

/**
* @ClassName: ExcelUtil
* @Description: Excel导入导出工具类
* @author 周宣
* @date 2016-11-8 下午7:16:11
*
*/
public class ExcelUtil {
private static final Logger logger = Logger.getLogger(ExcelUtil.class);

/**
* @Title: createWorkbook
* @Description: 判断excel文件后缀名，生成不同的workbook
* @param @param is
* @param @param excelFileName
* @param @return
* @param @throws IOException
* @return Workbook
* @throws
*/
public Workbook createWorkbook(InputStream is,String excelFileName) throws IOException{
if (excelFileName.endsWith(".xls")) {
return new HSSFWorkbook(is);
}else if (excelFileName.endsWith(".xlsx")) {
return new XSSFWorkbook(is);
}
return null;
}

/**
* @Title: getSheet
* @Description: 根据sheet索引号获取对应的sheet
* @param @param workbook
* @param @param sheetIndex
* @param @return
* @return Sheet
* @throws
*/
public Sheet getSheet(Workbook workbook,int sheetIndex){
return workbook.getSheetAt(0);
}

/**
* @Title: importDataFromExcel
* @Description: 将sheet中的数据保存到list中，
* 1、调用此方法时，vo的属性个数必须和excel文件每行数据的列数相同且一一对应，vo的所有属性都为String
* 2、在action调用此方法时，需声明
*     private File excelFile;上传的文件
*     private String excelFileName;原始文件的文件名
* 3、页面的file控件name需对应File的文件名
* @param @param vo javaBean
* @param @param is 输入流
* @param @param excelFileName
* @param @return
* @return List<Object>
* @throws
*/
public List<Object> importDataFromExcel(Object vo,InputStream is,String excelFileName){
List<Object> list = new ArrayList<Object>();
try {
//创建工作簿
Workbook workbook = this.createWorkbook(is, excelFileName);
//创建工作表sheet
Sheet sheet = this.getSheet(workbook, 0);
//获取sheet中数据的行数
int rows = sheet.getPhysicalNumberOfRows();
//获取表头单元格个数
int cells = sheet.getRow(0).getPhysicalNumberOfCells();
//利用反射，给JavaBean的属性进行赋值
Field[] fields = vo.getClass().getDeclaredFields();
for (int i = 1; i < rows; i++) {//第一行为标题栏，从第二行开始取数据
Row row = sheet.getRow(i);
int index = 0;
while (index < cells) {
Cell cell = row.getCell(index);
if (null == cell) {
cell = row.createCell(index);
}
cell.setCellType(Cell.CELL_TYPE_STRING);
String value = null == cell.getStringCellValue()?"":cell.getStringCellValue();

Field field = fields[index];
String fieldName = field.getName();
String methodName = "set"+fieldName.substring(0,1).toUpperCase()+fieldName.substring(1);
Method setMethod = vo.getClass().getMethod(methodName, new Class[]{String.class});
setMethod.invoke(vo, new Object[]{value});
index++;
}
if (isHasValues(vo)) {//判断对象属性是否有值
list.add(vo);
vo.getClass().getConstructor(new Class[]{}).newInstance(new Object[]{});//重新创建一个vo对象
}

}
} catch (Exception e) {
logger.error(e);
}finally{
try {
is.close();//关闭流
} catch (Exception e2) {
logger.error(e2);
}
}
return list;

}

/**
* @Title: isHasValues
* @Description: 判断一个对象所有属性是否有值，如果一个属性有值(分空)，则返回true
* @param @param object
* @param @return
* @return boolean
* @throws
*/
public boolean isHasValues(Object object){
Field[] fields = object.getClass().getDeclaredFields();
boolean flag = false;
for (int i = 0; i < fields.length; i++) {
String fieldName = fields[i].getName();
String methodName = "get"+fieldName.substring(0, 1).toUpperCase()+fieldName.substring(1);
Method getMethod;
try {
getMethod = object.getClass().getMethod(methodName);
Object obj = getMethod.invoke(object);
if (null != obj && "".equals(obj)) {
flag = true;
break;
}
} catch (Exception e) {
logger.error(e);
}

}
return flag;

}

public <T> void exportDataToExcel(List<T> list,String[] headers,String title,OutputStream os){
HSSFWorkbook workbook = new HSSFWorkbook();
//生成一个表格
HSSFSheet sheet = workbook.createSheet(title);
//设置表格默认列宽15个字节
sheet.setDefaultColumnWidth(15);
//生成一个样式
HSSFCellStyle style = this.getCellStyle(workbook);
//生成一个字体
HSSFFont font = this.getFont(workbook);
//把字体应用到当前样式
style.setFont(font);

//生成表格标题
HSSFRow row = sheet.createRow(0);
row.setHeight((short)300);
HSSFCell cell = null;

for (int i = 0; i < headers.length; i++) {
cell = row.createCell(i);
cell.setCellStyle(style);
HSSFRichTextString text = new HSSFRichTextString(headers[i]);
cell.setCellValue(text);
}

//将数据放入sheet中
for (int i = 0; i < list.size(); i++) {
row = sheet.createRow(i+1);
T t = list.get(i);
//利用反射，根据JavaBean属性的先后顺序，动态调用get方法得到属性的值
Field[] fields = t.getClass().getFields();
try {
for (int j = 0; j < fields.length; j++) {
cell = row.createCell(j);
Field field = fields[j];
String fieldName = field.getName();
String methodName = "get"+fieldName.substring(0, 1).toUpperCase()+fieldName.substring(1);
Method getMethod = t.getClass().getMethod(methodName,new Class[]{});
Object value = getMethod.invoke(t, new Object[]{});

if(null == value)
value ="";
cell.setCellValue(value.toString());

}
} catch (Exception e) {
logger.error(e);
}
}

try {
workbook.write(os);
} catch (Exception e) {
logger.error(e);
}finally{
try {
os.flush();
os.close();
} catch (IOException e) {
logger.error(e);
}
}

}

/**
* @Title: getCellStyle
* @Description: 获取单元格格式
* @param @param workbook
* @param @return
* @return HSSFCellStyle
* @throws
*/
public HSSFCellStyle getCellStyle(HSSFWorkbook workbook){
HSSFCellStyle style = workbook.createCellStyle();
style.setFillForegroundColor(HSSFColor.GREY_25_PERCENT.index);
style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
style.setBorderBottom(HSSFCellStyle.BORDER_THIN);
style.setBorderTop(HSSFCellStyle.BORDER_THIN);
style.setLeftBorderColor(HSSFCellStyle.BORDER_THIN);
style.setRightBorderColor(HSSFCellStyle.BORDER_THIN);
style.setAlignment(HSSFCellStyle.ALIGN_CENTER);

return style;
}

/**
* @Title: getFont
* @Description: 生成字体样式
* @param @param workbook
* @param @return
* @return HSSFFont
* @throws
*/
public HSSFFont getFont(HSSFWorkbook workbook){
HSSFFont font = workbook.createFont();
font.setColor(HSSFColor.WHITE.index);
font.setFontHeightInPoints((short)12);
font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
return font;
}

public boolean isIE(HttpServletRequest request){
return request.getHeader("USER-AGENT").toLowerCase().indexOf("msie")>0?true:false;
}
}